Unprotected sex, guy didn't finish, but late period?

Slightly worried, the day after my last period ended I had unprotected sex. But the guy didn't finish, he just wanted to make me cum (which he did😍) because no guy had ever made me cum before so he wanted to be my first. My period is now a couple days late so I'm slightly worried even though he didn't finish. (He finished himself when he got home later that night) He already had a little pre-cum before we actually started having sex just from being turned on.